In the field of heat exchangers for welding supplies, a number of basic configurations have been used. Typically, these systems include a reservoir, a motor for driving a fan and a coolant pump, a reservoir for containing coolant and a connection/control panel for making coolant connections to external welding equipment, and for controlling the heat exchanger itself.
In one configuration, the coolant reservoir is attached separately to the structural framework of the device, typically a metal framework. These configurations are typically rectangular in construction since the framework is made of sheet metal, easily formed into rectangular shapes. In these systems, a radiator is disposed at one end of the heat exchanger, the connection/control panel is disposed at the other end of the unit, and air is drawn in through the sides of the unit and is exhausted through the radiator. Such systems provide easy access to interior components by unscrewing and removing portions of the sheet metal outer skin. They also are easily stackable one on top of the other, or atop the welding power supply itself. A disadvantage to such systems is their complexity of construction, typically requiring many components that must be assembled separately.
In an alternative configuration, such as that disclosed in U.S. Pat. No. 5,121,788 issued on Jun. 16, 1992, to G. Carollo, the substantially rectangular structural elements forming the framework of the heat exchanger are replaced with a single hollow cylindrical element that serves as the chassis for a motor, fan, pump and radiator, and a reservoir for the coolant fluid. The radiator is disposed at one (open) end of the cylinder, and the motor with attached pump and fan is located within, and parallel to the central axis of, the cylinder. Due to this cylindrical design, the other end of the cylinder has no connection/control panel, but is open to allow air to flow axially through the cylinder and radiator. By providing a single resilient element that performs both a chassis function as well as a reservoir function, the complexity of the first configuration is avoided. As a result, however, there are several disadvantages: the connection/control panel is eliminated, there is no easy access to the internal elements of the device, and the system is not easily stacked.
There is a need, therefore, for an improved heat exchanger, especially a heat exchanger for welding machines. In particular, there is a need for heat exchangers with reduced complexity. A heat exchanger is needed having easy access to internal components. Furthermore, a heat exchanger is needed that provides easily accessible connectors and controls.